MRI SAFETY For First Responders Facility MRI Personnel

MRI SAFETY For First Responders, Facility & MRI Personnel https: //www. youtube. com/watch? v=fa. UBXr. J 9 PGk

First Responders are…. The people who arrive to help us with an emergency. ■ MR Personnel ■ FSU Police ■ FSU Fire ■ EMTs

Safety Zones The American College of Radiology has defined four safety zones within MRI facilities. These are denoted Zones I through IV and correspond to levels of increasing magnetic field exposure (and hence potential safety concern).

Zone 1: General Public ■ We have no Zone 1 at FSU MRI Research Facility. ■ All entrances are card swipe protected.

Zone 2: First contact point between visitors and staff ■ This is the area where subjects will be screened, change, experience the mock scanner and wait for the test. ■ Subjects and non-MR personnel are not free to move about this area unsupervised. ■ The only exception to this will be cleaning staff and FSU Police and Fire staff who have had Level 1 MR Safety Training or MR First Responders Safety Training.

Zone 3: Region of potential hazardous energy related to the electromagnetic environment ■ Only MR personnel and prescreened subjects may enter this zone. MR personnel are staff that have completed the Level 2 MR Safety Training, have an approved metal screening form on file and have participated in the MR Safety Briefing for Emergency Procedures. ■ Zone 3 is always locked.

Zone 4: Room housing the magnet ■ Zone 4 is always contained in Zone 3 and the same training and screening requirements apply. ■ The most immediate danger associated with a magnetic environment is the attraction between the magnet and ferromagnetic objects. ■ Ferromagnetic objects can become airborne projectiles when placed in a strong magnetic field, moving with a terminal velocity of 60 mph.

Level 1 Personnel ■ Level one personnel are individuals who have not had MR safety training. ■ The designation of Level 1 Personnel typically applies to visitors and volunteers. ■ Level 1 Personnel must be accompanied by Level 2 or Level 3 Personnel in all zones of the MRIF.

Level 2 Personnel ■ Level 2 MR Personnel are individuals who have viewed and passed the MR safety training as approved by the MRIF Oversight Committee. ■ An MRI Metal Screening form must be on file in the MRIF office. ■ The designation of Level 2 Personnel typically applies to undergraduate and graduate research assistants, post-doctoral fellows, and research assistants from individual laboratories. ■ Level 2 Personnel are permitted to be in all areas of MRIF up to Zone 3, but may not enter the MRI Scanner Room (Zone 4). ■ Level 2 Personnel may have keycard access the MRIF facility but are not permitted to be there alone. ■ Documentation of Level 2 Personnel qualifications must be submitted, updated at least annually, and must be signed by the MRI Technologist, representing the MRIF Executive Committee. Records of documentation must be maintained within MRIF.

Level 3 Personnel ■ Level 3 Personnel are individuals designated as sufficiently trained to be in the MRIF on their own (except when a participant is being scanned, during which time, two persons are required. ■ They are also sufficiently trained to oversee the MR screening process and screen individuals to undergo imaging. ■ These individuals must demonstrate knowledge of the broad aspects of MR safety issues, including, for example, issues related to the potential for thermal loading or burns, and direct neuromuscular excitation from rapidly changing gradients. ■ They must also demonstrate specific knowledge regarding the safety procedures within MRIF. ■ Level 3 Personnel are permitted to be in the MRI facility alone and to supervise Level 1 and 2 MR Personnel when they are in the facility. ■ Level 3 Personnel may be permitted control room access, but are restricted from the Scanner Room unless under the supervision of a Level 4 Personnel. ■ Documentation of Level 3 Personnel qualifications must be recorded submitted, updated annually, and must be signed by the MRI Technologist representing MRIF Oversight Committee. Records of documentation must be maintained within the MRIF.

Level 4 Personnel ■ Only registered MRI Technologists are level 4 personnel. ■ Level 4 personnel are the only individuals that will operate the MR Scanner. ■ Documentation of Level 3 Personnel qualifications must be recorded submitted, updated annually, and must be signed by the MRI Technologist representing MRIF Oversight Committee. Records of documentation must be maintained within the MRIF.

Fields in the MR Environment ■ Static Magnetic Field – Attraction – Torque ■ Gradient Fields ■ Radiofrequency Field(RF)

Static Magnetic Field: Attraction ■ Attraction is the force that is exerted on ferromagnetic objects into the scanner. ■ The static magnetic field affects external objects brought into the scanner room as well as metallic implants within a person. ■ Remember, the magnet is ALWAYS ON! NEVER bring any metal objects into the scanner rooms.

Hazards of the Static Magnetic Field Metal in the Scanner Room ■ Projectiles - The most immediate danger associated with a magnetic environment is the attraction between the magnet and ferromagnetic objects. ■ Ferromagnetic objects can become airborne projectiles when placed in a strong magnetic field. ■ The strength of the field increases super linearly as you approach the bore, and even hand-held objects can be jerked free, very suddenly, as the holder moves closer. ■ Small objects, such as paper clips and hairpins, can have a terminal velocity up to 60 mph when pulled into a 3 T magnet and larger objects go even faster!

Things that should never go into the scanner room Pocket Litter and Clothing Phones, keys, hairpins, hearing aids, jewelry, watches, Fit Bit and similar monitors, bank or credit cards, FSU swipe keys, pens, pocket knives, safety clips, nail clippers, coins, money clips, steel toed boots, clothes with metal threads, to name a few. Items Used for Work Hand-held tools, electric tools, tool belts, nails or screws, brooms, mop buckets, vacuum cleaners, aerosol cans, paint cans, guns, knives, axes, non MRI compatible fire extinguishers, electronic equipment, scissors, stretchers, medical boxes, etc.

Hazards of the Static Magnetic Field Metal In the Body ■ Metallic objects in the body can also have dangerous effects when placed in a magnetic field. ■ Ferromagnetic metal implants or metal fragments may twist or move, causing internal injury and/or DEATH. ■ The safe fringe field for a person with a pacemaker is the 5 gauss line, or just inside the control room door (Zone 3). ■ No person with any electronic implants may enter the control room.

People with the following devices that should never to into the scanner room In the Body Aneurysm clips, cardiac pacemakers, internal defibrillators, internal pumps or shunts, infusion pumps, electronic implants or devices, neuro stimulators, spinal cord stimulators, cochlear implants, implanted hearing aids, implanted drug devices, prosthetic implants, metallic fragments from accidents or metal injuries, shrapnel, On the Body Insulin infusion pumps, hearing aids, prosthetic limbs, EKG monitors, blood pressure monitors

Static Magnetic Field: Torque ■ Torque, is the twisting force that the static magnetic field exerts on a ferromagnetic object to bring it into alignment. ■ Torque’s attractive force is more heavily exerted on an elongated object that is perpendicular to the magnetic field.

The Magnet is ALWAYS On! Hospital beds weigh about 170 pounds. People can get trapped between a ferromagnetic object and the magnet.

Emergency Procedures **In Case of Emergency, Call 9 -911** Physical Location: Suite G 135, Medical School Research Bldg. (#4002) College of Medicine Florida State University 1115 West Call St. Tallahassee, FL 323064300

Fire Evacuation Plan Meeting Place

If We Encounter a Small Fire or Smoke ■ We will attempt to extinguish it with our MR Compatible fire extinguisher. ■ If it becomes obvious that we need to call the Fire Department, we will follow our emergency procedures and call 9 -911. ■ Once Firefighters, Police Officers, or EMTs arrive, we will remind them of the dangers of Zones 3 and 4.

In the Case of a Electrical Sparking or Signs of Smoke Emergency Electrical Shut down Procedure • There are three electrical power off buttons, one inside the magnet room, one is in the control room and one is in the equipment room. Make sure that it is the power shutdown button, but be careful NOT to inadvertently depress the quench button. (You can tell the difference because the electrical power off buttons are uncovered, the quench buttons are not. ) • Press the Table stop button. • Manually release the table bed and remove the volunteer from the scanner.

Manual table removal When the scanner shuts down or power is lost, manually remove the volunteer from the scanner. • 1 Press the Table stop button. 1 • 2 Pull the table release lever. • 3 Pull the table slowly away from the magnet using the handle at the foot of the bed. • Carefully remove coils. • Help the volunteer off the table. 3 2

If We Encounter a Large Fire ■ If we encounter a fire, electrical sparks or smoke that we cannot manage ourselves, we will call 9 -911, Fire emergency, and we will follow our emergency procedures. ■ A large fire may require us to allow the fire department access to the MRI Suite. ■ If Fire personnel need to enter the magnet room in order to put out a fire, we will “Quench” the magnet.

MRI Magnet Quench A quench is when the cryogens (liquid helium) are rapidly released, or “boiled off” from the magnet through a vent into the outside air. This will render the MRI Scanner inoperable and it is very expensive to ramp up the magnet (about 40, 000 dollars). Ramping up the magnet is refilling the cryogens and recalibrating the scanner. There are ONLY 2 Situations requiring a Quench: ■ If there is a fire in the magnet room that cannot be put out using a non-magnetic fire extinguisher and requires the assistant of the fire department. ■ If any individual is pinned to the magnet, trapped or in a life-threatening situation by a non-removable ferrous object.

Emergency Quench Procedure ■ Evacuate the magnet room but leave the door open. ■ Depress one of the “Magnet Stop” buttons. One is inside the magnet room and one is in the control room. ■ An alarm will sound and the Magnet Stop button will light up. ■ Do not touch helium ducts in the magnet room. ■ With temperatures hundreds of degrees below freezing, cryogens are cold enough to freeze human tissue within seconds, and pose serious cold burn and frostbite hazards.

NOTE: In the absence of a major emergency, facility users should never quench the magnet by themselves.

Safety Training……. . . (continued) FOR MRI PERSONNEL

Subject Safety in the MR Suite Non Ferromagnetic Metals • Metals that aren’t attracted to the magnet can still interact with the magnetic field. • They can cause local distortions in the images. • They can electrically conduct energy. Ferromagnetic Metals • Ferromagnetic objects pose a missile-related hazard. • Exposure may cause serious injury as a result of movement or dislodgment of the metallic foreign body.

Metal Screening • Anyone that is going to enter the MR console or magnet room MUST be metal screened. • Subjects who have any medical devices or implants on or within their bodies may not be scanned. • Any female subject who is pregnant or is possibly pregnant may not be scanned. • Subjects who have had an incident or injury of metal fragments from grinding, welding, drilling, traffic accident, explosion, shooting or shrapnel in their eyes or body may not be scanned. • All medicine patches must be removed prior to being scanned.

Metal Screening • Tattoos can heat up during a scan. Ensure subject is warned and is instructed to alert MR personnel if any burning occurs. • Subjects with dental braces will not be scanned due to artifacts. Fillings in molars can also produce artifacts, especially in EPI sequences. • All orthodontic devices should be removed prior to a scan. Non-removable dental work have the potential for discomfort and should be explained to the subject. Instruct the subject to alert MR personnel is any discomfort is experienced. • Cosmetics that contain metal can produce distortions of the magnetic field around the eye and obscure the orbit on the image. It can also cause a heating sensation on the eyelid. It is recommended that subjects remove all eye makeup before the exam. • All objects must be removed from the pockets and off the body of anyone entering the scanner room.

Remember those Forces • Static Magnetic Field • Attraction • Torque • Gradient Fields • Radiofrequency Field (RF)

Gradient and RF Forces ■ Gradients produce changes in the magnetic field over short periods of time. ■ Radiofrequency Pulses, (or RF pulses) are used in the spin preparation phase of a pulse sequence, which prepare the spin system for the ensuing measurements. ■ These rapidly varying fields induce oscillating currents in the body and can cause involuntary stimulation of nerves and muscles.

Metal Screening • As the prevalence for fabrics containing non-detectable metallic microfibers increases, we will have all subjects change into a gown. • Both a handheld magnet and a Ferromagnetic metal detector should be used to additionally screen an individual entering the magnet room, not as a substitute. They should NEVER be used to screen an individual who has not been deemed safe to enter the magnet room since they do contain weak magnets and can disrupt pacemakers or cause metal fragments in the eye to move. • If there any doubts about questions on the metal screening form, do not allow the individual into the magnet room.

Specific Absorption Rate (SAR) • In order to form images, time varying fields in the form of radio pulses (and gradient pulses) are needed. As these fields pass through the conductive tissues of the body they generate electrical currents that circulate within body tissues. • The body tissues are resistive however, so that the circulating current loses energy to the body in the form of heat. • The rate at which the body absorbs heat energy during scanning is known as the “Specific Absorption Rate” or SAR

Specific Absorption Rate (SAR) SAR is carefully monitored during MR scanning, but for these measurements to be accurate several assumptions must be met. • The body weight of the subject must be entered correctly, as the allowed dose varies by body weight. • The calculations assume that there are no foreign conductive objects in the magnetic field. • It is assumed that the instrument is functioning properly.

Specific Absorption Rate (SAR) • It is very important to understand that in our Siemens Prisma system, that during scanning of the head, the entire body is exposed to high power RF signals. Heating can occur in any part of the body during a head scan. • The natural cooling of the body is very effective in healthy individuals. However, covering the subjects in blankets, or wearing heavy clothing reduces the efficiency of body cooling. • Be sure that your subjects understand that it is not normal to become uncomfortably warm during an MRI exam. • The subject should be told to squeeze the patient alert ball if they feel any discomfort.

High Risk Subjects Certain individuals are at much higher risk of problems from SAR, specifically, these conditions may present additional cause for concern: diabetes obesity cardiovascular disease fever sedation old age use of diuretics use of beta blockers hypertension using muscle relaxers NOTE: If your subject has any of these conditions you must pay particular attention and in many cases you should consult a physician before scanning.

RF Safety • Avoid skin to skin contact that might create a low resistance electrical current loop. • At radio frequencies, current can pass through a vacuum and across insulated wires. Keep a sufficient distance between any wires or cables and the skin. • Avoid any crossing or looping of RF cables by running them in straight lines. • It is a good idea to run all cables parallel to the magnetic field - along the tube that makes up the magnet bore. • Keep cables from different components, such as EKG, RF and EEG separated.

Other Safety Concerns Ear plugs or Headphones • Echo planar Imaging (EPI) and other fast gradient sequences produce high levels of noise ranging from 126 -131 d. B on a 3 T system. • Anyone in the magnet room while it is in operation is required to wear hearing protection. Squeeze Ball • The squeeze ball allows subjects to set off an alarm to gain the attention of the MRI operator. • It should be given to all subjects and they should be instructed to use the alarm in the case of any discomfort during the MRI Exam.

Temperature Control • The air conditions within MR Magnet room will affect the rate of cooling of the subject. The temperature should not exceed 72 degrees and the humidity should not exceed 60 percent or drop below 40 percent to ensure excessive heating does not occur. • Blankets can be provided to subjects who are cold, but the MR Operator must explain that they should squeeze the alarm ball if they become too warm. The MR Operator must stay in verbal contact with them in between series over the intercom to ensure that they are not becoming too warm.